They're
changing the color of money. I don't know why free marketers aren't more up-in-arms about this development. The green dollar bill is a valuable literary symbol, demonstration of power, unique American-ness in a world of Monopoly money, and many more things.
It's like changing the color of the flag without asking anyone. And, forming a synecdoche, it's being done in the name of security when there are several other options.